The present invention relates to a power converter integrated solar cell module having a power converter mounted on the rear surface of a solar cell module.
Presently, the global environment has increasingly attracted attention, so research and development of solarlight power generating systems have been extensively made. The form of solarlight power generating systems (photovoltaic power generating systems) presently widely used is that a plurality of solar cell modules are connected in series to construct a solar cell array, and electric powers from these solar cell modules are collected and input to a power converter.
Recently, however, a power converter integrated solar cell module has spread which is obtained by mounting a power converter having the same capacity as that of one solar cell module on the rear surface of the solar cell module.
Compared to the conventional solarlight power generating systems, this power converter integrated solar cell module has the following advantages:
DC circuit wiring can be omitted.
Cost reduction by the inverter mass production effect can be expected.
Since maximum power point control is performed for each module, the power unbalance when an array circuit is installed can be minimized.
The solar cell module can be installed in any place because the commercial frequency/standard voltage is readily obtainable by one module.
Unfortunately, this power converter integrated solar cell module has the following problems.
The temperature of the front surface of the solar cell module reaches 70xc2x0 C. to 80xc2x0 C. in midsummer, and the heat is conducted to the rear surface to increase its temperature. Therefore, if an inverter is simply mounted on the rear surface of the solar cell module, the heat conducted from the front surface heats the inverter to interfere with heat dissipation of the inverter, thereby lowering the conversion efficiency. In the worst case, the heat may destroy internal electric devices of the inverter.
To solve this problem, Japanese Patent Laid-Open No. 9-271179 has proposed a structure in which an inverter is mounted on the rear surface of the solar cell module with a spacing between them.
If, however, an inverter is mounted with a spacing, a projection on the rear surface of the solar cell module increases. This restricts a place where the solar cell module can be installed, reducing the merit of the power converter integrated solar cell module that it can be used in various places.
Also, a special member is necessary to mount an inverter on the rear surface of the solar cell module with a spacing between them, and the assembly process is complicated. This increases the manufacturing cost.
The present invention has been proposed to solve the conventional problems, and has as its object to provide a low-cost, high-reliability power converter integrated solar cell module.
According to a preferred aspect of the present invention, the foregoing object is attained by providing a power converter integrated solar cell module comprising a solar cell module, and a power converter attached to a relatively-low-temperature portion on the rear surface of the solar cell module.
The present invention is characterized in that the power converter is attached to the end portion of the solar cell module.
The present invention is characterized in that a solar cell installation area is made smaller than the area of the rear-surface reinforcer of the solar cell module, and the power converter is attached to a portion of the solar cell module rear surface where no solar cell is present.
The present invention is characterized in that a solar cell installation area is made smaller than the area of the rear-surface reinforcer of the solar cell module, a surface of the rear-surface reinforcer on which the solar cell is placed has a color different from that of the surface of the solar cell, and the power converter is mounted on the solar cell module rear surface whose color has a higher light reflectance of the two colors.
The present invention is characterized in that a solar cell installation area is made smaller than the area of the rear-surface reinforcer of the solar cell module, at least part of a portion where no solar cell is placed of a surface of the rear-surface reinforcer on which the solar cell is placed has a color having a light reflectance higher than that of the surface of the solar cell, and the power converter is mounted on the solar cell module rear surface in that portion.
The present invention is characterized in that the light reflectance of a covering material in a portion of the solar cell module where no solar cell is present is made higher than that of the covering material in a portion where the solar cell is present, and the power converter is mounted on the solar cell module rear surface in the portion where no solar cell is present.
The present invention is characterized in that the external color of the power converter has a light reflectance higher than that of the color of the solar cell module rear surface.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.